I went to do my weekly water change on Bill's tank today and I noticed my fish looks a bit bloated. I feed a little more than I used to but not a lot. A small pinch of flake food and some goes to the floor that my Pygmy Corydoras eat up.

Housing
What size is your tank? 10 gallons
What temperature is your tank? 78
Does your tank have a filter? Yes Wisper 10i
Does your tank have an air stone or other type of aeration? No
Is your tank heated? Yes
What tank mates does your betta fish live with? 1 nerite 5 pygmy corydoras and a crap load of pond snails

Food
What type of food do you feed your betta fish? omega one flake food
How often do you feed your betta fish? 1x a day

Maintenance
How often do you perform a water change? every 7-10 days
What percentage of the water do you change when you perform a water change? 25-50% depending on how fast I can clean the gravel while the syphon is going
What type of additives do you add to the water when you perform a water change? API Water conditioner

Water Parameters:
Have you tested your water? If so, what are the following parameters?

Symptoms and Treatment
How has your betta fish's appearance changed? Bloated, see pictures. Where Egg spot would be on female
How has your betta fish's behavior changed? None - Still swims around like normal
When did you start noticing the symptoms? Today, Might have been like this for about a week.
Have you started treating your fish? If so, how? Not yet
Does your fish have any history of being ill? No - I got him in July from Petsmart
How old is your fish (approximately)? See above question

I don't want to do salt unless I need to since his tank mates are Corys. There are also pond snails in his tank and they have been in the tank since just after I set it up from getting a plant at LFS -

The day I brought him home

Today

I can put the cory's in my 29 gallon tank and the snail as well if I need to salt the tank. I can't raise the temp above the 78 it sits at now cause I have one of those tetra automatic heaters

What do you guys suggest?

On a side note - if you look at the most resent pictures you'll see a hole in his bottom fin. It isn't a tear. It's hard to see but when he's flared it's a perfect circle. Has anyone seen this before? It's been there since I got him. Never gotten bigger. It's like someone poked him with a needle and it's never healed. I'm not worried about it, I just find it odd. Actually looking at the top picture the hole is there.. yep, odd!

You should be doing a weekly water change + siphon cleaning not letting it go to week and a half. Nitrates are high. You clean your gravel right, not just take off the top? With your bioload I would be aiming for weekly 50%s. I would do at least one 50% change now, and probably another 50% one tomorrow as well.

His rays are really messy. Looks like he's got some fin rot too.. or more tears.. holes like that are due to overflaring, ammonia burns (most commonly), or tears.

Some bettas don't do well with flake food and it can cause constipation issues. He should also be getting one fast day a week no matter what you feed. I QT him, and not feed for a couple days and see if it doesn't go down on its own. Meanwhile watch his poop and see what it looks like. If his poop isn't white, stringy or clear (meaning normal colored brown ball is what I expect to see) and his stomach goes down you can start treating the fin rot with aquarium salt at one tsp per gallon predissolved. You can do this for up to 10 days and only need to readd with a water change. You only need to add back as much salt as water you change. How much/frequently depends ont eh size of the QT.. just needs to be something you can keep warm either by floating in the main tank (wouldn't QT in less than 1g) or a separate heater. Stress coat at 1 ml per 1 gallon can also help with fin regrowth.

I am using the API master test kit
I posted the nitrates at 20-40 since on the kit it's all the same color on the comparison chart
I normally do a water change every Saturday with a gravel vac ... I suction the corners and front of his tank and move the plants around to get around them too. I rarely go more than 7 days but if I'm busy on the weekend they get done on tuesday (mondays are busy for me). Also once a week I sift his gravel around so if anything pop's up his filter can suck it up.

His fins are actually fine. I had him flare once for me to make sure .. they are so long that they're curly when he's not flaring. I've never owned a crowntail before so it's new to me as well.

I actually fast him on the day of the water change. I feed Friday afternoon when I get home from work then again on Sunday afternoon.

I don't have a QT but I can look around for a 1 gallon something or other to put him in and yeah float him in the tank so it stays heated. That way I don't have to move the corydoras to another tank.

he is pooing today as usual. It's a brownish/red color (his flakes are red) and I fed him about 1/4th of a blanched frozen pea which he gobbled up. I also put him in some epsom salts for about 15 minutes (about 1.5 tsp/gal) but he started freaking out cause he hates the 1 gal fish bowl I have so I put him back in his tank. I will just have to keep an eye on him. Tomorrow I can do a water change on his tank again.

I checked him this morning and his eyes are normal. Not cloudy like he has a cataract. Same as my other betta. I haven't fed him and if he's getting food its going to be baby snails in his tank. He does eat squished ones sometimes. Do you think snail shells could be to blame? Maybe he ate a piece that he can't pass..